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What Eats Diatoms In An Aquarium?

Diatoms can cause a number of problems for people in the fish keeping hobby and will often cause issues for fish keepers of all levels of experience ranging from someone who is brand new to the hobby all the way up to people who have been keeping fish for decades.

You can try to do everything perfectly in your tank and then suddenly end up with a diatom bloom spreading brown algae all over your substrate and ruining the visual appeal.

Due to this, it is easy to see why we see so many people reaching out and asking various questions about how they are able to deal with a diatom breakout in their tanks with most people looking for something that eats diatoms to help them clean the bloom up.

It is actually surprisingly difficult to find something that is able to reliably consume large quantities of diatoms due to their small size so the majority of people have to opt for snails rather than a fish.

Still, there are a number of options for diatom eaters that you are able to add to your aquarium that is having problems with a diatom bloom to help you get the situation under control as quickly as possible.

We will be covering some of the more common questions that we see from the community in this article though and offering some recommendations for some potential new additions to your tank that will be able to eat the diatoms to help control their population.

What Eats Diatoms In An Aquarium?

The best option for eating diatoms in an aquarium are definitely snails with nerite, cerith, trochus, and in some situations conch snails being excellent options to eat the diatom bloom in your aquarium.

If you only need the snails for eating the diatom bloom then cerith snails are probably the best option to go with as they will eat the most diatoms relative to their size.

If you order your cerith snails online then they can workout to be less than one dollar per snail too helping to keep your costs as low as possible.

Some people do prefer the mixed bags that contain both nerite and cerith snails too as this can maximise the benefits that you get from your snails with other types of algaw in your tank too while also drastically reducing the amount of diatom growth in the tank too.

Although trochus snails and various species of conch can work when it comes to eating diatoms in your aquarium, we would usually recommend that our readers avoid them as they tend to eat other things in your aquarium too.

If you literally just want something to eat the diatoms in your tank then go with nerite snails and cerith snails as they are low maintenance and can eat large amounts of diatom at a rapid pace.

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Do Any Fish Eat Diatoms?

Some algae eating fish may eat diatoms and the brown algae build up, it is really not the prefer food of algae eating fish and they will usually leave it in favour of other types of algae or detritus in your tank.

This is why we recommend that you go with snails to eat your diatoms rather than fish in the majority of aquariums as it is a much easier and cheaper option for getting your diatom build up under control.

One thing that we have seen people report is that the fry and baby fish of certain species will eat large amounts of diatoms but we would never recommend that you breed fish just for this purpose.

If you have fry and baby fish available then give them a go at eating your algae bloom but keep in mind that other fish in your tank may see the fry and baby fish as a potential food source.

Just going with snails and leaving them to get the job done is usually the best option and should be your primary consideration when looking for something to eat the diatom build up in your tank.

Depending on the size of your tank, a couple of cerith snails may be able to get the job done without needing a large number of snails too as they really do eat a large amount of diatoms relative to their small size.

Will Diatoms Die Out On Their Own?

A diatom algae bloom will eventually die out on its own as it runs out of a suitable food source.

A very common food source for diatoms is silica but they can feed on other nutrients in your tank too but once all of the nutrients have been consumed, you will usually find that the diatom bloom will rapidly fade.

Unfortinatley, some tanks have enough food for the diatoms to live for months and thrive before they end up getting to this stage.

We have seen people use water changes of their tank to rapidly decrease the nutrient content in their water as well as scrub their surfaces in the aquarium as well as vacumme their substrate as best they can to try and reduce the amount of time that the diatoms can live in their tank.

This can work but the nutrients in your tank may be used by other organisms that you have such as other live plants, corals or anemones so it can be a gamble.

If you do have a reliable gravel vacuum then you are able to try and remove the diatom growth on your substrate each time it builds up but this is usually too much time and effort than its worth.

You will usually fine that the diatom bloom grows at such a rapid pace that you are essentially just wasting your time manually removing it when you could just use a couple of cerith snails to just eat the bloom instead.


That brings our article going over what eats diatoms in an aquarium to an end. We hope that we have been able to help you better understand what you should be aiming for when it comes to a new addition to your tank to keep the diatom bloom undercontrol. Most people initially try a traditional algae eater fish or crab but they tend to not eat much of this type of algae where as snails will usually eat huge amounts of it without issue.